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公开(公告)号：US10883861B2
公开(公告)日：2021-01-05
申请号：US15555628
申请日：2016-03-07
Applicant: Silixa Ltd.
Inventor： Mahmoud Farhadiroushan , Tom Parker , Sergey Shatalin
Abstract: An optical fiber distributed acoustic sensor system includes weak broadband reflectors inserted periodically along the fiber. The reflectors reflect only a small proportion of the light from the DAS incident thereon back along the fiber, typically in the region of 0.001% to 0.1%, but preferably around 0.01% reflectivity per reflector. In addition, to allow for temperate compensation to ensure that the same reflectivity is obtained if the temperature changes, the reflection bandwidth is relatively broadband. In some embodiments the reflectors are formed from a series of fiber Bragg gratings, each with a different center reflecting frequency, the reflecting frequencies and bandwidths of the gratings being selected to provide the broadband reflection. A chirped grating may also be used to provide the same effect. In preferred embodiments, the reflectors are spaced at half the gauge length i.e. the desired spatial resolution of the optical fiber DAS.
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Patent Agency Ranking
公开(公告)号：US10393572B2
公开(公告)日：2019-08-27
申请号：US15368945
申请日：2016-12-05
Applicant: Silixa Ltd.
Inventor： Mahmoud Farhadiroushan , Tom Richard Parker , Sergey Shatalin
Abstract: The present invention provides novel apparatus and methods for fast quantitative measurement of perturbation of optical fields transmitted, reflected and/or scattered along a length of an optical fiber. The present invention can be used for point sensors as well as distributed sensors or the combination of both. In particular this technique can be applied to distributed sensors while extending dramatically the speed and sensitivity to allow the detection of acoustic perturbations anywhere along a length of an optical fiber while achieving fine spatial resolution. The present invention offers unique advantages in a broad range of acoustic sensing and imaging applications. Typical uses are for monitoring oil and gas wells such as for distributed flow metering and/or imaging, seismic imaging, monitoring long cables and pipelines, imaging within large vessel as well as for security applications.
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公开(公告)号：US20180245957A1
公开(公告)日：2018-08-30
申请号：US15962196
申请日：2018-04-25
Applicant: SILIXA LTD. , CHEVRON USA INC.
Inventor： Mahmoud Farhadiroushan , Daniel Finfer , Veronique Mahue , Tom Parker , Sergey Shatalin , Dmitry Strusevich
Abstract: Embodiments of the present invention provide a cable for optical fiber sensing applications formed from fiber wound around a cable core. A protective layer is then preferably placed over the top of the wound fiber, to protect the fiber, and to help keep it in place on the cable core. The cable core is preferably of a diameter to allow bend-insensitive fiber to be wound thereon with low bending losses. The effect of winding the fiber onto the cable core means that the longitudinal sensing resolution of the resulting cable is higher than simple straight fiber, when the cable is used with an optical fiber sensing system such as a DAS or DTS system. The achieved resolution for the resulting cable is a function of the fiber winding diameter and pitch, with a larger diameter and reduced winding pitch giving a higher longitudinal sensing resolution.
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公开(公告)号：US09989388B2
公开(公告)日：2018-06-05
申请号：US15029480
申请日：2014-10-15
Applicant: SILIXA LTD. , Chevron U.S.A. Inc.
Inventor： Mahmoud Farhadiroushan , Daniel Finfer , Veronique Mahue , Tom Parker , Sergey Shatalin , Dmitry Strusevich
CPC classification number: G01F1/661 , G01D5/3537 , G02B6/4415
Abstract: Embodiments of the present invention provide a cable for optical fiber sensing applications formed from fiber wound around a cable core. A protective layer is then preferably placed over the top of the wound fiber, to protect the fiber, and to help keep it in place on the cable core. The cable core is preferably of a diameter to allow bend-insensitive fiber to be wound thereon with low bending losses. The effect of winding the fiber onto the cable core means that the longitudinal sensing resolution of the resulting cable is higher than simple straight fiber, when the cable is used with an optical fiber sensing system such as a DAS or DTS system. The achieved resolution for the resulting cable is a function of the fiber winding diameter and pitch, with a larger diameter and reduced winding pitch giving a higher longitudinal sensing resolution.
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公开(公告)号：US20180045543A1
公开(公告)日：2018-02-15
申请号：US15555628
申请日：2016-03-07
Applicant: Silixa Ltd.
Inventor： Mahmoud Farhadiroushan , Tom Parker , Sergey Shatalin
CPC classification number: G01D5/35374 , G01D5/35306 , G01D5/3537 , G01H9/004
Abstract: An optical fiber distributed acoustic sensor system includes weak broadband reflectors inserted periodically along the fiber. The reflectors reflect only a small proportion of the light from the DAS incident thereon back along the fiber, typically in the region of 0.001% to 0.1%, but preferably around 0.01% reflectivity per reflector. In addition, to allow for temperate compensation to ensure that the same reflectivity is obtained if the temperature changes, the reflection bandwidth is relatively broadband. In some embodiments the reflectors are formed from a series of fiber Bragg gratings, each with a different center reflecting frequency, the reflecting frequencies and bandwidths of the gratings being selected to provide the broadband reflection. A chirped grating may also be used to provide the same effect. In preferred embodiments, the reflectors are spaced at half the gauge length i.e. the desired spatial resolution of the optical fiber DAS.
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公开(公告)号：US20160169712A1
公开(公告)日：2016-06-16
申请号：US15048315
申请日：2016-02-19
Applicant: Silixa Ltd.
Inventor： Mahmoud Farhadiroushan , Tom Richard Parker , Sergey Shatalin
CPC classification number: G01H9/004 , E21B47/0002 , E21B47/101 , G01D5/35303 , G01D5/35306 , G01D5/35325 , G01D5/35335 , G01D5/35358 , G01D5/35364 , G01D5/35377 , G01D5/35383 , G01F1/66 , G01F1/661 , G01M11/331 , G01V1/40
Abstract: Apparatus and methods for fast quantitative measurement of perturbation of optical fields transmitted, reflected and/or scattered along a length of an optical fibre can be used for point sensors as well as distributed sensors or the combination of both. In particular, this technique can be applied to distributed sensors while extending dramatically the speed and sensitivity to allow the detection of acoustic perturbations anywhere along a length of an optical fibre while achieving fine spatial resolution. Advantages of this technique include a broad range of acoustic sensing and imaging applications. Typical uses are for monitoring oil and gas wells such as for distributed flow metering and/or imaging, seismic imaging, monitoring long cables and pipelines, imaging within large vessel as well as for security applications.
Abstract translation: 用于快速定量测量沿光纤长度传输，反射和/或散射的光场的装置和方法可用于点传感器以及分布式传感器或两者的组合。 特别地，该技术可以应用于分布式传感器，同时极大地延长了速度和灵敏度，以允许在沿着光纤长度的任何地方检测声学扰动，同时实现精细的空间分辨率。 该技术的优点包括广泛的声学感测和成像应用。 典型用途用于监测油气井，例如用于分布式流量计量和/或成像，地震成像，监测长电缆和管道，在大容器内成像以及安全应用。
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